Effect of Instrument–Assisted Soft Tissue Mobilization versus Muscle Energy Technique Over Sternocleidomastoid in Patients with Chronic Non-Specific Neck Pain

Background: Chronic non-specific neck pain (CNSNP) is a prevalent musculoskeletal condition that adversely impacts individuals’ functional abilities and general well-being. Increased activation of the sternocleidomastoid (SCM) muscle has been implicated in the pathophysiology of CNSNP, yet few studies have directly compared targeted interventions on this muscle. Instrument-Assisted Soft Tissue Mobilization (IASTM) and Muscle Energy Technique (MET) are emerging manual therapy approaches aimed at improving musculoskeletal dysfunctions.   
Objectives: This study aimed to compare the effects of IASTM and MET applied to the SCM, on neck pain, range of motion (ROM), and functional impairment in patients with CNSNP.
Patients and Methods: A single-blind, randomized controlled trial (RCT) was conducted involving 56 participants with CNSNP, who were randomly allocated into three groups: Group A (control) received hot packs and standard neck and scapular exercises; Group B received IASTM applied to the SCM muscle in addition to the control protocol; and Group C received MET applied to the SCM muscle alongside the control protocol.
Results: Both experimental groups showed statistically significant improvements in VAS scores, NDI scores, and cervical ROM compared with the control group. The IASTM group demonstrated greater improvement in neck extension, right and left rotation, lateral flexion, and reduction in pain and disability compared to both MET and control groups. 
Conclusion: IASTM and MET applied to the SCM muscle are both effective in alleviating pain, improving cervical ROM, and decreasing functional disability in individuals with CNSNP. IASTM may offer slightly greater benefits, particularly in enhancing cervical mobility. These findings suggest the use of targeted manual therapy approaches for managing CNSNP.